Method and Apparatus for Underground Oil Extraction

ABSTRACT

There is provided a portable oil extraction system comprising one or more high heat energy generators that supply high heat energy to an underground oil-rich zone. Each heat energy generator comprises a chamber for gasifying used rubber tires, waste oil, coal or other combustible materials for the production of volatile gases and high energy heat. Exhaust gases from the heat generator are piped underground into a zone of oil-rich material such as oilsands, oilshale, or contaminated soil to heat the oil-rich material therein to vaporize the hydrocarbons. Vacuum pressure withdraws the vaporized hydrocarbons from the underground oil-rich zone. The vaporized hydrocarbons are condensed and collected within a forced-air condenser for reuse. An optional second stage refrigeration unit condenses any residual vaporized hydrocarbons that may be missed by the forced-air condenser. No water or chemical additives are used in this environmentally benign process.

FIELD OF THE INVENTION

The present invention relates to an apparatus for extracting oil from oilsand, oil shale, or contaminated soil, and particularly relates to such an apparatus which is portable and the use of which is non-polluting.

BACKGROUND OF THE INVENTION

Vast amounts of hydrocarbon fuels are stored within geological structures known as oilsands and oilshale. As more easily extracted sources of hydrocarbon fuels are depleted, increasing attention is paid to methods for extraction of oil from oilsands and oilshale.

Oilsand, also known as tarsand, is a naturally occurring mixture of sand or clay and bitumen, a dense hydrocarbon. The bitumen may be processed into usable oil. Worldwide reserves of oil from oilsand are estimated to exceed 3 trillion barrels.

Oil shale is a fine-grain sedimentary rock containing a solid mixture of chemical compounds, known as kerogen, from which hydrocarbons may be extracted. Processing of oil shale can convert the kerogen into usable crude oil. Global deposits of oil from oil shale are estimated to be approximately 3 trillion barrels.

Various systems and methods have been attempted to remove oil from soil, sand, or other earthen materials. One of these devices is shown in U.S. Pat. No. 5,193,291, which teaches a conventional “baghouse” system wherein the contaminated soil is heated directly by a gas furnace flame. The heated soil is then discharged into the baghouse for subsequent separation and discharge. U.S. Pat. No. 5,272,833 shows a similar apparatus and process for remediating contaminated soil. This system is also a baghouse-type system.

U.S. Pat. No. 5,188,041 discloses a soil remediation process comprising passing non-oxidizing heated gases over the contaminated soil at a flow rate and temperature to prevent surface drying of the contaminated soil. This system is specifically a low-temperature system, and therefore is incapable of effectively isolating oil from oilsands or oilshale.

U.S. Pat. No. 5,004,486 discloses a gas cleaning system that directs the exhaust gas from the combustion chamber through a heat exchanger for cooling the gas, and into a bubbling dust separator submerged under water in order to discharge the gas directly into the water for the prevention of air pollution.

U.S. Pat. No. 5,273,355 discloses a rotary drum mechanism for incinerating soil and mixing the soil with heated and dried stone aggregate for the production of asphalt paving. The gas products of combustion from the incinerator are directed into the rotary drum to be further combusted prior to direct discharge into the atmosphere.

U.S. Pat. No. 5,302,118 discloses a soil remediation system comprising a rotary drum having a burner flame directed into one end of the drum, as in U.S. Pat. No. 5,193,291. In addition, as in the '291 Patent, the '118 Patent includes the baghouse-type collection mechanism for collecting dust to prevent its release into the atmosphere.

The prior art methods of oil extraction from oil-rich material require use of water, require addition of harmful chemicals, or cause air pollution or accumulation of toxic waste. It would be desirable to have a method and apparatus for underground oil extraction from oilsand, oil shale, and contaminated soil which does not require water or addition of chemicals, and which is environmentally benign.

SUMMARY OF THE INVENTION

According to one embodiment of the present invention, there is provided a portable oil extraction system comprising one or more heat energy generators that supply heat energy to an underground oil-rich zone. Each heat energy generator comprises a chamber for gasifying used rubber tires, waste oil, coal or other combustible materials for the production of volatile gases and high energy heat. Hot exhaust from the heat energy generators is directed through piping into the underground oil-rich zone. Oil-rich material such as oilsands, oilshale, or contaminated soil forming the oil-rich zone is heated by the hot exhaust, in excess of 300° F., to vaporize the hydrocarbons. Vacuum pressure withdraws the vaporized hydrocarbons from the underground zone through more piping. The vaporized hydrocarbons are condensed and are collected within a forced-air condenser for recycling. An optional second stage refrigeration unit may be used to condense any residual vaporized hydrocarbons that may be missed by the forced-air condenser. There is provided an oil extraction apparatus for extracting oil from underground oil-rich material, comprising at least one heat energy generator, each heat energy generator comprising a vaporization chamber for receiving and holding waste materials to be vaporized, air supply means for supplying air under slight pressure into the vaporization chamber, fuel supply means for supplying fuel into the vaporization chamber; a volatile gas withdrawal manifold communicating with the vaporization chamber for withdrawing volatile gases from the vaporization chamber; a mixing chamber having a volatile gas inlet communicating with the volatile gas withdrawal manifold, air pressure means for introducing pressurized air thereinto, a fuel injector, and ignition means for igniting a gas fuel air mixture, and an outlet; and a combustion chamber that communicates with the mixing chamber outlet, the combustion chamber having an outlet, inlet piping for carrying heated exhaust gas of the heat energy generator into an underground oil-rich zone; condensing means for condensing the hydrocarbon vapor from exhaust gases; outlet piping for carrying vaporized hydrocarbons from the underground oil-rich zone to the condensing means, and a blower to create vacuum pressure to draw the vaporized hydrocarbons toward the condenser means.

Each heat energy generator and the condenser means may be mounted on skids for portability. The apparatus may further include a second-stage hydrocarbon recovery system comprising a water-cooled condenser and freon refrigeration heat exchanger.

The apparatus may use two or more heat generators. The heat energy generator vaporization chamber and the oil extractor housing may have linings of a refractory material. The vaporization chamber may have openings in at least one wall for ingress of air. The openings may have a diameter of between 2.5 and 3.5 inches, ideally 3 inches. There may ideally be 12 openings.

There is provided a method of oil extraction from an underground source comprising use of the above described apparatus to extract useable oil from an underground oil-rich material. The oil-rich material may be oilsand, oil shale, or contaminated soil. The method of extracting oil from an underground source is achieved without the use of water, and without the addition of chemical additives.

BRIEF DESCRIPTION OF THE DRAWINGS

A detailed description of the preferred embodiments is provided below by way of example only and with reference to the following drawings, in which:

FIG. 1 is a schematic diagram of the oil extraction apparatus of the present invention;

FIG. 2 is a schematic diagram of the oil extraction apparatus of the present invention, showing more than one burner for generating heat energy for oil extraction; and

FIG. 3 is a schematic diagram of the oil extraction apparatus of the present invention; showing more than one burner for generating heat energy for oil extraction.

In the drawings, one embodiment of the invention is illustrated by way of example. It is to be expressly understood that the description and drawings are only for the purpose of illustration and as an aid to understanding, and are not intended as a definition of the limits of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description of the invention, reference numerals are used to identify structural elements, portions of elements, or surfaces in the drawings, as such elements, portions or surfaces may be further described or explained by the entire written specification. For consistency, whenever the same numeral is used in different drawings, it indicates the same element, portion, surface and area as when first used. It should be understood that only those components having particular functional importance or that would not otherwise be identified have been assigned reference numerals.

The oil extraction apparatus of the present invention comprises a three-stage system. The first stage is a combustion chamber that combusts waste materials such as used vehicle rubber tires into high energy heat by gasification in a continuous-burn cycle.

The heat energy from the first stage is fed into the second stage, which is an underground oil-rich zone 24 which may be oilsand, oil shale, contaminated soil or another oil-rich formation. The heat energy is directed through piping from the generator into the oil-rich zone. This high heat is applied to the oilsand, oilshale or contaminated soil directly so that the hydrocarbons within the oil-rich zone may be vaporized.

The volatile hydrocarbon vapors are then drawn off by vacuum created by an above ground blower and introduced via a vertical conduit 26 into the third stage, which is an air-cooled condenser and hydrocarbon recovery system. This recovery system condenses the hydrocarbon vapors from the volatile exhaust gases piped to the surface from the heated underground oil-rich zone to permit reclamation of the hydrocarbons and a clean exhaust gas to be emitted into the atmosphere.

Referring now to the drawings, the system of the present invention is shown schematically. In the schematic of FIG. 1, heat energy for extracting oil from the underground oil-rich zone 4 is provided by a heat energy unit 2. Fuel for the heat energy units may be provided by used rubber tires, waste oil or other fuel sources. Ignition of the fuel in the heat energy generators may be provided by a propane source. The heat energy unit injects heated air 3 directly into the underground oil-rich zone through inlet piping 6 to act directly on the oil-rich material underground. Soil, sand or other solids remaining after removal of volatile hydrocarbons are left in place at their source. As indicated in FIGS. 2 and 3, more than one heat energy unit may be used.

After passing through the oil-rich zone, the hydrocarbon-bearing heated air 7 is drawn out of the ground by a blower 10. Volatile hydrocarbon vapors 13 emitted from the oil-rich material are drawn from underground through outlet piping 8, and passed using a motor 9 and a blower 10 through a forced-air condenser 12. The volatile hydrocarbon vapors are condensed in the condenser and stored in an oil storage tank 14. The cooled air 15 is passed through a second condensing unit 16 to complete hydrocarbon removal. The cleaned air 17 is then exhausted.

In operation, with the heat generator furnace filled with used tires and/or other fuel source, air is blown into the furnace at a plurality of locations adjacent the lower portion of the furnace. Propane may be injected into the furnace and ignited by a propane injector and, along with the inflow of air (oxygen), ignites the fuel. When a sufficient operating temperature is reached, further propane is unnecessary to maintain combustion of the tires within the furnace. The inflow of air into the furnace is controlled to maintain sufficient oxygen to permit the tires and other waste material to maintain combustion in a continuous-burn mode, and gasify the waste material through dry distillation. Adequate oxygen supply is provided by a plurality of openings in the side of the furnace. The plurality of openings permits improved combustion and greater efficiency. The effect of this is to allow a wide variety of fuels to be burned. The fuels may include used rubber vehicle tires, coal, waste oil, or other materials. This increase in efficiency also permits use of relatively small, portable heat generators.

As the gasification furnace 22 is a closed system, as the used tires combust and vaporize, exhaust gases in excess of 300° F. are generated within the furnace. These gases are permitted to exhaust from the furnace via the inlet piping into the underground oil-rich zone.

The furnace, its associated manifolds, air injectors, etc., may be mounted on a pair of skid rails. In this manner, the first stage of the apparatus of the present invention can be readily transported, along with the third stage, to a desired site for direct on-site extraction of underground oil from oil-rich zones.

One or more blowers 10 draw the vaporized hydrocarbons that are vaporized in the process from within the underground oil-rich zone to the third stage of the system, the hydrocarbon condenser. The vacuum pressure applied by the blower 10 draws the vaporized hydrocarbons from the oil-rich zone into the forced-air condenser 12, as shown in the schematic of FIG. 1.

It should be appreciated that the forced-air condensing unit uses air at ambient temperature for condensing the vaporized hydrocarbons from the exhaust gases. In most instances, this works quite well to recover essentially all of the vaporized hydrocarbons from the exhaust gases from the outlet piping 8. In unusually warm climates, however, air at ambient temperature may not be adequate to fully condense all of the vaporized hydrocarbons from the exhaust gases. In these instances, a second stage in the condensing process may be utilized. Exhaust gases from the forced-air condensing unit 12 that still contain trace amounts of vaporized hydrocarbons are drawn through a closed collection unit. The collection unit includes a series of condensing coils. The vaporized hydrocarbons pass through the condensing coils and are condensed on the coils and collect at the bottom of the collection unit for periodic removal. The remaining clean exhaust gases exit the closed collection unit at the outlet to be exhausted to atmosphere.

The condensing coils communicate directly with a heat exchanger to transfer heat from the condensing hydrocarbons to the heat exchanger. These condensing coils carry a mixture of 30% glycol and water, maintained at approximately 30° F. The heat exchanger transfers heat from the glycol and water mixture to a conventional freon refrigeration circuit that draws heat from the freon and distributes it to atmosphere in a conventional manner.

Whether the oil extraction system of the present invention utilizes only the forced-air condenser or both the forced-air condenser and the refrigeration unit chiller, exhaust gases are drawn through the system by an exhaust fan located at the point of exhaust to the atmosphere. In either configuration, the exhaust fan provides the vacuum to draw the vaporized hydrocarbons through the system for condensation and reclamation, and exhausts the cleaned gases to atmosphere.

It is to be noted that the apparatus of the present invention provides a means of extraction oil from oilsand, oil shale, contaminated soil or other oil-rich material without the use of water or the addition of chemicals which may be harmful to the environment.

From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objectives herein set forth, together with other advantages which are obvious and which are inherent to the apparatus. It will be understood that certain features and sub-combinations are of utility and may be employed with reference to other features and sub-combinations. This is contemplated by and is within the scope of the claims. As many possible embodiments may be made of the invention without departing from the scope of the claims. It is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. It will be appreciated by those skilled in the art that other variations of the preferred embodiment may also be practised without departing from the scope of the invention. 

1. An oil extraction apparatus for extracting oil from underground oil-rich material, comprising: (a) at least one heat energy generator, each heat energy generator comprising (i) a vaporization chamber for receiving and holding waste materials to be vaporized; (ii) air supply means for supplying air under slight pressure into the vaporization chamber; (iii) fuel supply means for supplying fuel into the vaporization chamber; (iv) a volatile gas withdrawal manifold communicating with the vaporization chamber for withdrawing volatile gases from the vaporization chamber; (v) a mixing chamber having a volatile gas inlet communicating with the volatile gas withdrawal manifold, air pressure means for introducing pressurized air thereinto, a fuel injector, and ignition means for igniting a gas fuel air mixture, and an outlet; and (vi) a combustion chamber that communicates with the mixing chamber outlet, the combustion chamber having an outlet; (b) inlet piping for carrying heated exhaust gas of the heat energy generator into an underground oil-rich zone; (c) condensing means for condensing the hydrocarbon vapor from exhaust gases; and (d) outlet piping for carrying vaporized hydrocarbons from the underground oil-rich zone to the condensing means; (e) a blower to create vacuum pressure to draw the vaporized hydrocarbons toward the condenser means.
 2. The apparatus of claim 1, wherein each heat energy generator and the condenser means are mounted on skids for portability.
 3. The apparatus of claim 1, further comprising a second-stage hydrocarbon recovery system comprising a water-cooled condenser and freon refrigeration heat exchanger.
 4. The apparatus of claim 1, wherein the at least one heat energy generator comprises two energy generators.
 5. The apparatus of claim 1, wherein the heat energy generator vaporization chamber and the oil extractor housing include linings of a refractory material.
 6. The apparatus of claim 1, wherein the vaporization chamber further comprises a plurality of openings in at least one wall for ingress of air.
 7. The apparatus of claim 8, wherein each of the openings has a diameter of between 2.5 and 3.5 inches.
 8. The apparatus of claim 9, wherein the plurality of openings comprises 12 openings.
 9. Use of the apparatus of claim 1 to extract useable oil from an underground oil-rich material.
 10. Use of the apparatus as in claim 9, wherein the oil-rich material is oilsand.
 11. Use of the apparatus as in claim 9, wherein the oil-rich material is oil shale.
 12. Use of the apparatus as in claim 9, wherein the oil-rich material is contaminated soil.
 13. A method of extracting oil from an underground source without the use of water.
 14. A method of extracting oil from an underground source without the addition of chemical additives.
 15. The method of claim 13 wherein the oil is extracted from an oil-rich material selected from the group of oil-rich materials comprising oilsand, oil shale, and contaminated soil.
 16. The method of claim 14 wherein the oil is extracted from an oil-rich material selected from the group of oil-rich materials comprising oilsand, oil shale, and contaminated soil. 